The fire emergency light is made of industrial plastic and high-brightness light bulbs. The color is mainly white. There are two arrows on the surface. , impact resistance and other characteristics. Fire emergency lights have wall-mounted, portable and hanging installation methods.
Fire emergency light
Protection class: IP65
Anticorrosion class: WF2
Explosion-proof mark: ExdIICT4
Advantages of fire emergency lights
With the advantages of reliable operation, high stability and long life, it is suitable for high-rise buildings such as factories, hotels, shopping malls, and buildings. For lighting, metal lamp caps or flame retardant plastic lamp caps are used, and there are wall-mounted, portable and hanging installation methods. Emergency time ≥ 90min.
Working principle of fire emergency light
1. Battery charging circuit
Outside The power supply charges the battery with constant current through Q2, Q6, R8 and D10. When there is an external power supply, the charging current will charge the battery through R8 and D10, and the charging indicator D12 will be lit.
2. Lamp control circuit
It is composed of Q3, still, Q5, Q7 and keys K and G. When there is no mains power, press the K (on) key once, and Q5 is saturated On, the collector current of Q5 keeps Q7 on through R12; D11 reverses breakdown and works in a regulated state, and the collector voltage of Q5 provides bias to Q3 and Q4 to turn on and light up L1 and L2. When the G (off) key is pressed once, Q7 is turned off, the conduction condition of Q5 is removed, and the light is turned off.
When there is mains power supply, the external power supply makes D7 reversely cut off through D9, Q5 cannot be turned on, and keys K and G cannot control the on and off of lights L1 and L2.
After the power failure, the potential of the negative electrode of diode D7 becomes zero, which makes it conduct forward in an instant, and Q5 is saturated and conducts, which constitutes the lighting circuit condition, and L1 and L2 are lit.
After a power is received, the negative electrode potential of D7 becomes high and reversely turns off, Q5 turns off, and the light goes out (plays the role of automatic control). In the lighting control circuit, D7 and Q7 work in a critical state through R6, and the switch keys K and G only play a triggering role.
3. Test circuit
When pressing and holding the test button S, Q1 is turned off, the negative potential of D7 becomes low and the positive bias is turned on, so that Q5 is turned on to meet the lighting conditions. Light up L1 and L2. Release the S button and the light will turn off. The function of the test circuit is to test whether the lighting circuit is normal.
4. Power circuit
The 220V AC is transformed by the transformer, rectified and filtered, and the 4.6V DC voltage is output from the Ql collector. Mainly provided to the charging circuit to charge the battery. And through R9, D14 is illuminated to indicate.
5.k The barrier display circuit consists of D13, Q8, R17 and D11 to form a fault indication circuit. If the external power supply voltage is too high to make Q8 turn on, D13 will turn on the voltage fault.
Emergency time of fire emergency lights
The 2005 edition of the Fire Protection Code for Design of High-Rise Civil Buildings It is said in the above: emergency lighting and evacuation indication signs, batteries can be used as backup power, and the continuous power supply time is not less than 20 minutes; the continuous power supply time of high-rise buildings with a height of more than 100 meters should not be less than 30 minutes, but in the current The standard is 90 minutes.
The emergency time of fire emergency lights is different for different products.
The emergency time of the emergency light depends on the place of use and the requirements of the fire safety protection level.
Some other brands of fire emergency lighting, although their own emergency lighting time can reach this length, but when the fire emergency lighting stops external power supply, it truly enters the emergency lighting state, and the lighting is in the emergency lighting state. After working for 60 minutes, the light appears dim, the light irradiance emitted by the lamps is obviously weakened, and the penetrating power of the light is suddenly reduced, the effect of emergency lighting cannot be achieved, and the fire safety protection level is greatly reduced;
Strictly speaking: As long as it is a fire emergency light, when it enters the normal emergency lighting working state after a power failure, the time when the lighting fixture appears dim within a predetermined period of time cannot be counted as the normal working time of the emergency light.
The emergency lighting time of the fire emergency lights is related to the power of the light source configured by the fire emergency lights and the power of the battery pack that matches the emergency lights;
Some brands of fire emergency lights , the emergency time is more than 30 minutes; these should be selected based on comprehensive factors such as the specific use environment of the emergency light and the current actual required safety protection level.
How to turn off the fire emergency lights
The fire emergency lights usually come with their own batteries, which are generally in a charging state after wiring and power transmission, basically consuming electricity It can be ignored, and once the power is turned off, the lamp will start the electric energy lighting of the emergency battery. Generally, the light will be turned off after 60-90 minutes of power consumption. When the power supply is not connected, the experiment button is one-time. Startup cannot be stopped.
Some emergency lights have a test button on the shell, which can control the lighting or extinguishing of the emergency lights when the emergency lights are not connected to the lighting power supply.
